Fluid-pressure tool.



PATENTBD MAY14,"1907.

G. H. GILMAN. FLUID PRESSURE TOOL.

APPLICATION FILED IDIJO. 19. 1905.

mim W 1 FHI llx Innvenor Georlgefl Gilman.

ZL'n/e use@ WL', azz

- hammer'.

sfrariis PAT "INT FFICE.

GEORGE H. GiiiMAN, or OLAREMONT, NEW HAMPsHiRE, AssioNoR Tok sULLivAN MACHINERY COMPANY, or OLAREMONT, NEW HAMP- sHiRE, A CORPORATION OE MAINE.

FLUiD-PRESSURE TOOL..

Specification of Letters Patent.

Patented May 14, 1907.

Application tied December 19,1905. serial No. 292,418.

lNew Hampshire, have invented an Improvement in Fluid-Pressure Tools, of which the following description, inconnection With the accompanying drawings', is av specification, 'like letters on the drawings representing like arts. p My invention relates to fluid pressure engines, such as are operated by compressed air or other elastic iluid, .and is more particularly though not exclusively concerned with the provision of a new and improved pneumatic My invention will be best understood by reference toV the following specification When ltaken in connection with the accompanying illustration of one specific embodiment thereof submitted for illustrative purposes, While its scope will be more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a longitudinal central section taken throughl a pneumatic hammer embodying one form of my invention and showing the controlling valve and the piston in one position; Fig. 2 is a 'similar y ysectional view showing the valve and piston in different positions; Fig. 3 is a section on the line 3 3, Fig. 1 g' Fig. 4 is a section on the line 4-1l in Fig. '1; Fig. 5 is an end view-0n an enlarged scale of the transverse control ling valve employed in the hammer illustion of the saine.

Referring to the drawings and to the specitic embodiment of my invention there illustrated. the cylinder' a is threaded into the chambered headb, the cylindrical valve block c acting as a closure for that end of the cylinder which. is entered within the chamber. '.lhe cylinder and valve block are maintained in the necessary alinement required for the registration of their connecting passages by means ol' dowel pins (not shown). ,Slidably fitted over thehe'ad'end of the casing is the grasping handle e, secured thereto and guided thereon by thehollow threaded stud f, which latter passes through the slot e inthe basecf the handleuthehandle thereby having a limited movemiit toward and away fromthe casing.

and, Fig. is a side eleva- The head or casing is provided with a constant pressure chamber g, facing the valve block to which chamber, when the tool is in use, air or other elastic fluid is constantlyl supplied through the inlet f within the hollow stud and thence through the supply passage f2.

For -control of the air admission to the pressure chamber there is provided a longitu din'ally arranged throttle valve lying across and controlling the passage f2 and compris# ing the piston heads L and h of equal diames ter and. separated by the neck or contracted portion h2. The piston portion h works in a cylindrical cup or pocket suitably formed in the head, to the bottom of which leads the auxiliary pressure duct i, the lower end of the piston head h being thereby exposed to a constantly acting pressure. When the tool is pressed against its Work the hand. pressure upon the sliding handle acts against the head i of the throttle valve and forces the latter into the position shown with the vcontracted portion lying across the supply passage and permitting free passage therethrough of the supplied pressure. When the operator withdraws the tool from the Work and relieves the pressure of;A his hand against the grasping handle, the constantly acting duid pressure uponthe'piston head h at the forward end of the throttle valve forces the latter back against the handle and pushes the handle Outward upon the casing. The valve follows the handle inits movement until the latter is brought to rest against the stud f, this movement of the valve" being sufficient to bring the valve piston lheadfh across'the lsupply passage in position to close the same.

The cylindrical valve block c has a transversely arranged valve chamber within which -works the differential valve d, employed to control the piston movement. The valve chamber consists of a diametrical passage having a reduced end portion d', to which live pressure is constantly admitted from the constant pressure chamber g, through the pressure supply duct d2. The valve chamber is closed at each'end by the sleeve s, which embraces the entire valve block.

Live pressure is admitted from the oonstant pressure chamber ber, through the unobstructed admission pasy sage gifthe latter having a rectangular cross g, to the valve chain' IOO shape and size.

opposite and larger end of the valve chamber.

During the forward movement of the pis;

ton, the valve is held in the position shown' in Figrl, by the pressure constantly acting upon the reduced end (Z4, during which time active pressurel is freely admitted to the head end of the cylinder to drive, the piston for- Ward and deliver the blow upon the'` tool shank t, the latter heing held within the usual sleeve or bushing t.

During the forward movement of the piston the controlling valve 'is reversed by the admission oi' iiuid pressure to the larger end of the -valve chamber, this acting against the larger valve end to overhalance the pressure upon the smaller end and move the valve to the position shown in Fig. 2. This valve reversing pressure is received through a longitudinal intermittent pressure port j, which, opening interiorly into the cylinder at j', and extending lengthwise through the cylinder walls and the valve block, connects the interior of the cylinder with the'larger end of the valve chamber. This intermittent pressure `port is intermittently placed in communication throughpiston movement with a constant pressure port 7c, which latter, extending longitudinally from the constant pressure chamber g through the valve block and the cylinder walls, opens within the cylinder at le. The piston has themain. or larger portion Z Working within the main cylinder chamber and the reduced forward portion Z, adapted to enter the contracted cylinder walls e on the forward piston niovenient to close the cylinder -to the tool space beyond. The

main cylinder portion is provided with a pair of separated circumferential grooves Z2 connected by the several longitudinal and eXterior grooves or depressions Z3. Formednpon the interior Walls ofthe cylinder and aliuing With the openings g" and. 7c ,respectively, are the' interior peripheral grooves y"24 and 7c.

vVlfhen on the forward piston movement the forward' piston groove Z2 crosses the cylinder groove j2, the intermittent pressure port is immediately placed in communication wit i a constant pressure port-ir, through the system `o" grooved connecting piston passages, and

y the pressure acting upon the enlarged valve end instantly moves the same into the resure to the position shown, in. F ig. l

,ser

versc position shown in Fig In this reversed position ol the valve the cylinder passage q2 is cult oli' from the admission passage g by the interposition ot the enlarged'milve portion and placed in communication with the exhaust through the opening or chamher d formed upon the exterior 'of the valve which opening connects the cylinder with the exhaust passage m the latter leading into the annular space surrounding the valve block and communicating with the exterior through the radial exhaust passages m. At the same `time the admission passage g is placed iu comi'nunicatiou with the tool end pressure port 'n hy means ot the interiorly formed valve passage (Z7. The tool end pressure port n'communicates with the interior ol the cylinder at the forward end thereof and, of. reversal of the valve, acts -to admit pressure from the constant pressure chamher q and the interior valve passage d'7 to the tool end of the cylinder, where acting upon the rcducedpistoa area between the enlarged and contracted piston )ort-ion, it is ell'ective in causing the instantaneous return. of the piston after its hlow has heen delivered, although iisullicient materially to reduce the piston momentum hefore the hlow is struck.

On its return mow/ment the pisterL cuts ollI pressure from the larger area ot the dillcrertial valve as soon as the forwaid piston groove Z2 crosses or passes the cylinder groove jl. Further reverse movement ol the piston withdraws the reduced portion Zfrom the cortracted cylinder walls, placing the tool erd .of the cylinder in commuuication with the tool space and the tool end exhaust passage o. This is acconu'ianicdor soon followed hy the uncovering of the cylinder groove f2 througlrfurther retraction of the piston, this acting to exhaust the pressure haer of the cui-- larged end of the valve and cause the return ol the same under the constantly actirfY prese this )osition pressure is avai admitted to the licad end oic the cylinder while cut oilN from the tool end thereof, the air at the tool end heirg exhausted through the exhaust ope.;- ing e. The momentum of the piston heing overcome hy the admission of air at the head end thereof, piston movement is reversed and it proceeds or. its forward stroke, as before described.

To relieve the valve of any pressure which might collect at the shoulder formed between the contracted and enlarged portions and thus retard the valve movement, an. exhausf or leakage )assage p is formed laterally i. the valve block c, and, opening into the a:- nular exhaust chamher, permits the escape of vany pressure which' might retard lhc valve.

The correct alinement of' the connertifg passages in the sleeve and the valve hlock is maintained hy n'icaus of the threaded pi;` r

and the proper'alinemeiit of the valve within the ilocli by meas ofthe pif. r.

It will be observed that the admission passage g from the constant pressure chamher to the valve chamber and the cylinder ably though not necessarily so reduced as to ,occupy but a small portion of the direct admission passage formed through the valve chamber and the valve block, therebypermitting a large part of the admitted pressure to pass on either side oi it with practically no obstruction whatever.

The provision ot grooved passage ways in or upon thepiston permits the effective intermi tteiit admission of pressure to ,the larger end ol`,tlic valve chamber without'disadvantageousl)Y reducing the bearing surface oi the piston. l

While I have illustrated and liselosed one embodiment ol my invention for illustrative purposes,- itis to be understood that the same is not limited to the details, forni orrrlative arrangement oi the parts disclosed, but that extensive modi'lieations thereof may be made without departing from the spirit oi' my invention.

(daim.

l. A dill'erential lluid'pressure engine having a dill'erential pistonA and a transverse dill'erential piston controlling valve', the latter provided with closed ends, an interme-j diate contracted neck portion about which pressure admission to one end of the cylinder takes place when the valve is suitably positloned, a constant pressure supply passage. in lateral communication with said neekand` an interior passage through whichpressure admission to the opposite cylinder end takes place whenthe valve is oppositely positioned.

2. A direct lluild pressure'engine having a dillerential piston and a transverse di tierentia-l piston controlling'valve, the latter provided With closed ends, ari intermediate contracted neck portionv about which pressure admission tothecylinder takes place when the valve isV suitably positioned, a lconstant pressure supply passage in lateral communication with 'said neck and an exterior chambered portion through which exhaust from the cylinder talxes place when the valve is i oppositely positioned and an interior passage through-which pressure admission to the op- *posite cylinder endrtalies place wheii`tlie' vential piston, and a transverse dillerential` valve is oppositely positioned.

3. A lluid pressure engine having a dill'erpiston controlling valve, the latter being provided with a contracted neck portion about which pressure admission to one end of the 'cylinder takes place when the valve is suitablypositioned, a constant pressure supply passage in lateral communicationwith said necl,y an exterior chambered portion through which exhaust from said cylinder end' takes place when the' valve is oppositely positionedJ and an interior passage through which pressure admission to tlie opposite cylinder en'd also takes place whenfthe valve is oppositel y positioned.

4. A iiuid. pressure engine vhaving a cylinder, a differential piston, a differential piston-controllingvalve provided with closed ends, and an interior assage through which pressure admission taies place to one .end of the cylinder and a' passage for admitting pressure to the opposite end of the cylinder, a passage leading from .the pressure supply and opening into the cylinder, a second passage leading from the cylinder to one end of said valve, separated circumferential grooves upon the piston and connecting passages between said grooves whereby when the piston is "suitably positioned the said two passages are placed in communication and pressure admitted to one end 'of the valve.

5. A luid pressure engine having a cylinder, a cylindrical valve block at the rear of said cylinder and forming a closure for the saine, a valve transversely mounted iii said block and of vsubstantially the longitudinal extent ofrsaid block a sleeve embracing the block and a cliambered head inclosing said valve, block and sleeve and having interior `threads ada ted to enga e with similar exterior threads -upon said cylinder which clamps the valve block and .said sleeve within t ie chamber of said head and between the same and the cylinder end.

6. A iluid pressure engine having a cylinder, a chambered head secured thereto, a cyliiidrical valve block within the cliainbered head and forming an end closure for the cylinder, a valve transversely arranged in said block -and a separate sleeve einl'iracing the said block and within said chainbered head and of substantially the-longitudinal extent of said block. 1

7. A fluid pressure engine comprising a cylinder and a piston, a transversely arranged diiierential valve having closed ends, an intermediate passage by which pressure admission to one end of the cylinder takes place when the valve is suitably positioned and an interior 4passage through which pressure admission takes place to theop osite cylinder end when the valve is opposite y positioned, said valve having aiiarea exposed to constant pressure and a larger area exposedto intermittent pressure, 'means for admitting pressure to the .larger area to reverse the valve on forward piston movement,

IIO

means acting through reversal offthe valve for admitting pressure to the tool end of the piston, a reduced piston portion slidable Within contracted cylinder Walls at the for- Ward end ofthe cylinder and an exhaust passage connecting the tool space in front of said contracted cylinder portion, the Withdrawal of said reduced piston portion from the contracted cylinder Walls ermitting pressure to exhaust from the toolp and from the larger area of the valve.

8. 'A fluid pressure engine having a-cylin.

der, a differential piston, a transversely arranged differential valve having'closed ends, an intermediate passage by which pressure admission to one end of the c vlinder takes place when the valve is suitab y ositioned and an interior passage through W lich pres" sure admission takes placel to the op osite cylinder end when the valve is opposite y po'- sitioned, said valve having an area exposed to constant pressure and a larger area 'exposed to intermittent pressure, means for admitting pressure to the larger end thereof to reverse the valve on forward movement of the piston7l means acting through reversal of the valve for admitting pressure' to the tool end ofthe piston, a reduced iston portion slidable within contracted cy luder walls at the forward en d of the cylinder, the withdrawal of said reduced piston portion from the contracted cylinder Walls permitting presend of said cylinder' trolled by said valve for admitting pressure alternately to oppositesides ol the pistou, and an exhaust passage leading from nuthin the cylinder near the forward end thereof and adapted to be uncovered by the rearward movement of the piston, saidv rearward movementactmg thereby both to exhaust the pressure from the tool end. of the cylinder and from the larger area of the vatve.

In testunony whereof, l have signed my name to this specification, in the presence el subscribing Witnesses. I

GEORGE ll. GllJtLLN.

Vtitnesses;

E. J. BRUCHARD,

JAMES A. Banen, DAvin P. .lfiin'ronnu 

